import React, { Component } from 'react';
import PropTypes from 'prop-types';
import { nanoid } from 'nanoid';

import './index.css'

export default class Header extends Component {

  static propTypes = {
    addTodo: PropTypes.func.isRequired
  }

  handleKeyUp = (e) => {
    const { keyCode, target } = e;
    let todoObj;

    if(target.value.trim() === '') {
      alert('输入不能为空！')
      return;
    }
    if(keyCode !== 13 ) return;

    todoObj = {
      id: nanoid(), 
      name: target.value,
      done: false
    }

    this.props.addTodo(todoObj);
    target.value = '';
  }

  render() {
    return (
      <input type="text" placeholder='请输入添加的事项，回车键确认' onKeyUp = { this.handleKeyUp }/>
    )
  }
}
